: It's a possibility. However, I think it makes the story unnecessarily
: complicated. In order to reach this conclusion, you have to speculate
: about the existence of something that is entirely outside the storyline as
: presented-- an A. I. that is never seen, mentioned, or heard from. It's a
: little like having a mystery story where a long-lost, never-spoken-of evil
: twin pops out of nowhere to be the villain.

: I think if this other entity existed, it would make most players feel a bit
: cheated.

: I still think that the simples explanation is the best-- "escaping
: convicts" means the Flood, and Cortana may or may not have lied to
: Foe Hammer for reasons as yet to be adequately explained.

Agreed...that is why I said "maybe not". The only "evidence" for another AI is from the Cortana Letters. Which as Miguel pointed out are a little suspect, considering that they came from Nathan.